Besides supplying Fe, high dust deposition also brings fine inorganic particles thatparticipate in particle aggregation and Fe scavenging. This study is aimed at a betterunderstanding how dust particles influence Fe speciation and residence time.A 1D-model of Fe biogeochemistry is coupled with the General Ocean TurbulenceModel and a NPZD-type ecosystem model. This model is applied for the TENATSOsite which is strongly influenced by Saharan dust events. Besides being affected byvarying dust deposition, the vertical distribution of different particle classes in themodel shows high sensitivity to changing aggregation rates, with dust particlesdominating near the surface and aggregates deeper down. The particle distributionplays a key role determining DFe loss through colloid formation and aggregation.Considering the redissolution of colloidal and particulate iron, modeled DFeconcentration vary in the same range as observations. Modeled Fe residence timesrange from months in surface waters to years in deeper waters.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 4: Synthesis: The Earth System from a Polar Perspective > WP 4.1: Current and Future Changes of the Earth System